asme b31.3 overview

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PROCESS PIPING ASME Code for Process Piping, B31.3

Muhammad Bilal June 01, 20131



Contents

Objective

History & Scope

Code Development History

Organization of Code

Scope

Exclusions

Design

Design Conditions

Design Criteria

Design for Internal Pressure (Para 304)

Fabrication, Assembly & Erection

Inspection, Examination & Testing



Objective

To provide the participant with a good basic understanding

of the design, fabrication, erection and inspection rules and

requirements of the ASME B31.3 Code. At the conclusion

of the session, the participant will understand:

Development history of the Code

How the ASME B31.3 is Organized

Design Conditions & CriteriaFabrication, Assembly & Erection

Inspection, Examination & Testing



HISTORY & SCOPE Code Development History Organization of Code

Scope

Exclusions

4



In 1926 the American Standards Association (ASA) initiated the B31 Project at the request of the American Society for Mechanical Engineers (ASME).

Members were required to be selected from engineering societies, industry, governmentbureaus, institutions and trade associations.

Initial publication in 1935 was entitled the “American Tentative Standard Code for Pressure

Piping”. This edition was directed toward power plant and industrial installations.

1942 Edition of “Code for Pressure Piping” added a new section for refrigeration piping &contained the following sections:

Power Piping Systems

Gas & Air Piping

Oil Piping Systems

District Heating Piping Systems

Refrigeration Piping Systems

Fabrication Details

Materials – Their Specifications and Identification

The “combined” edition of the code was published until 1955

History & Scope



Due to the size and complexity of trying to cover growing number of industrialapplications in one book, the Code was broken into separate documents.

In the 1960's, the Book Sections were formed and consisted of the following: B31.1 Power Piping

B31.2 Fuel Gas Piping

B31.3 Petroleum Refinery Piping

B31.4 Liquid Petroleum Transportation Piping Systems B31.5 Refrigeration Piping

B31.7 Nuclear Power Piping

B31.8 Gas Transmission and Distribution Piping Systems

B31.9 Building Services Piping

B31.10 Cryogenic Piping Systems

The B31.3 Code was first published in 1976 and represented a combined effort of two Committees, the old B31.3 which addressed petroleum refineries and relatedfacilities and the B31.6 which dealt with chemical plant piping. A draft code of theB31.6 was completed in 1974 but it was decided to publish one joint code, titledChemical Plant and Petroleum Refinery Piping. The first edition was published as

ANSI B31.3-1976.

History & Scope



The 1984 contained the integration of the B31.10 cryogenic requirements, a newstand alone chapter on high pressure piping was added to the code.

The 1990 and 1993 Editions added requirements for bellows expansion joints andaluminum flanges.

The 1996 Edition contained significant changes to the introduction and scopestatements to clarify the application of all B31 sections, which also revised their scope sections. The title of the code was changed to Process Piping. The 1996Edition also contains SI metric units and are designated as standard. Instructionsfor conversion are given where metric data are not available or it was not possible

to complete all the metric conversions to date. By agreement, either system maybe used.

In 2000 Edition, SI metric units are given first with US customary units inparentheses. (Tables H, X, Tables of Appendices A & K and Tables C-1, C-3 andC-6 in Appendix C are not converted into SI units). Values in metric units are to be

regarded as the standard, unless otherwise agreed between the contractingparties.

History & Scope



Organization of B31.3 CODE

FOREWORDINTRODUCTION

CHAPTE R ICHAPTER II

PART 1PART 2PART 3PART 4PART 5PART 6

CHAPTER IIICHAPTER IVCHAPTER VCHAPTER VICHAPTER VII

PARTS 1-6

PART 7PART 8PART 9PART 10

Chapter VIIIPARTS 1-10PART 11-20

CHAPTER IXPARTS 1-10

SCOPE AND DEFINITIONS

DESIGNCONDITIONS AND CRITERIAPRESSURE DESIGN OF PIPING COMPONENTSFLUID SERVICE REQUIREMENTS FOR PIPING COMPONENTSFLUID SERVICE REQUIREMENTS FOR PIPING JOINTSFLEXIBILITY AND SUPPORTSYSTEMS

MATERIALS

STANDARDS FOR PIPING COMPONENTS

FABRICATION, ASSEMBLY AND ERECTION

INSPECTION, EXAMINATION AND TESTING

NONMETALLIC PIPING &: PIPING LINED WITH NONMETALS(Prefix-A)Topics same as parts for Chapter

II MATERIALSPIPING COMPONENTS STANDARDSFABRICATION, ASSEMBLY AND ERECTIONINSPECTION, EXAMINATION AND TESTING

PIPING FOR CATEGORY M FLUID SERVICE (Prefix-M)Topics same as parts for Chapter VII Corresponding to Chapter VII

HIGH PRESSURE PIPING (Prefix-K)Topics same as parts for Chapter VII



Fluid Service Categories

Category D All discussions in B31.3 is based on this categoryNon toxic, non hazardous, non corrosive fluid below 150 psigpressure and at a temperature between -20 ~ 300 deg F

Category M Special requirements of chapter 8 to be fulfilledHazardous, harmful in small dozes to human beings, pressure andtemperature non falling in category D

Normal Fluid not falling in above two categories

High Pressure pipingThe pressure exceeds the limits of B16.5 class 2500 flange attemperatureB31.3 Chapter 9 details additional requirements



Scope of B31.3 (Para 300.1)

This Code prescribes requirements for the materials, design, fabrication, assembly, erection,examination, inspection, and testing of piping.

This Code applies to piping for all fluids:

Raw, intermediate, and finished chemicals;

Petroleum products;

Gas, steam, air, and water;

Fluidized solids; and

Refrigerants

This Code covers all piping within the property limits of facilities engaged in the processing or

handling of chemical petroleum, or related products. Examples are a chemical plant (including

non-radioactive fluids in a nuclear fuel reprocessing plant), petroleum refinery, loading terminal,

natural gas processing plant (including liquefied natural gas facilities), bulk plant, compounding

plant, and tank farm.

Packaged Equipment Piping - Piping which interconnects individual pieces or stages of

equipment within a packaged equipment assembly shall be in accordance with B31.3, except

that packaged refrigeration piping may conform to either B31.3 or B31.5.



Exclusions (Para 300.1.3)

The B31.3 Code excludes the following (Para. 300.1.3)

Piping systems designed for internal pressures 0 to 15 psi with design temperatures -

20°F to 366°F. (- 6.6°C to 185°C)

Power Boilers in accordance with ASME BPV Section I and boiler external piping

which is required to conform to B31.1; tubes, tube headers, crossovers, and manifolds of fired heaters, which are internal to

the heater enclosure;

pressure vessels, heat exchangers etc., pumps, compressors, and other fluid handling

or processing equipment, including internal piping and connections for external piping;

piping located on company property which has been set aside for pipelines conforming

to B31.4, B31.8, or B31.11, or applicable governmental regulations;plumbing, sanitary sewers, and storm sewers; and

fire protection systems constructed in compliance with insurance underwriters' or other

recognized fire protection engineering standards. (Requirements in NFPA Codes)



Exclusions (Para 300.1.3)

The B31.3 Code excludes the following (Para. 300.1.3)

a) Piping systems designed for internal gage pressures at or above zero but less than

105 kPa (15 psi), provided the fluid handled is nonflammable, nontoxic, and not

damaging to human tissues as defined in 300.2, and its design temperature is from

−29°C (−20°F) through 186°C (366°F)

b) Power boilers in accordance with BPV Code2 Section I and boiler external piping which

is required to conform to B31.1

c) Tubes, tube headers, crossovers, and manifolds of fired heaters, which are internal to

the heater enclosure

d) Pressure vessels, heat exchangers, pumps, compressors, and other fluid handling or

processing equipment, including internal piping and connections for external piping



DESIGN

Design Conditions Design Criteria

13



Design Conditions

Design Pressure (Para 301.2)

Design Temperature (Para 301.3)

Ambient Effects (Para 301.4)

Dynamic Effects (Para 301.5)Weight Effects (Para 301.6)

Thermal Expansion & Contraction Effects (Para 301.7)

Effects of Support, Anchor and Terminal Movements

(Para 301.8)Reduced Ductility Effects (Para 301.9)

Cyclic Effects (Para 301.10)

Air Condensation Effects (Para 301.11)




The pressure design of a piping system is based on determining thethickness of each piping component considering the following:

Design pressure of each component in the piping system shall not beless than the pressure at the most severe condition of coincident

internal or external pressure and temperature expected duringservice.

Design to achieve the greatest component thickness or highest flangerating required

Consider all pressure-temperature conditions and variations

Consider any exceptions to the Code requirements by particular attention to all statements in the subject paragraph. Para. 302.2.4

specifies the allowances for Pressure and Temperature Variations.




Provisions must be made to safely contain or relieve any

pressure to which the piping system may be subjected

(Para. 301.2.2).

Provide relief valving

Provide ability for isolation or

Design the system to withstand the highest pressure that

can be developed.

Consider oscillations, surges, control failures and

improper operation effects the piping system.




Consider that the allowances of Para. 302.2.4(f) are permittedprovided the other requirements of Para. 302.2.4 are also met.Para.302.2.4 addresses allowances for Pressure andTemperature Variations, it is a very detailed paragraph andshould be studied carefully before applying.

subject to owner's approval

operation in excess of pressure rating or the allowable stressfor pressure design at the temperature

33 % for no more than 10 hours at anyone time and no morethan 100 hours/year or

20 % for no more than 50 hours/year at anyone time and nomore than 500 hours/year

evaluation by the designer over the service life of the piping

system variations which are self-limiting



Design Temperature (301.3)

The design temperature of each component in a piping systemis the temperature at which, under the coincident pressure, thegreatest thickness or highest component rating is required.

Coincidental with pressure, the most severe condition is to beconsidered.

Consider the fluid temperature, solar radiation, heating or cooling temperatures.

Consider the material requirements and the minimum

temperature expected in service.Consider insulated and uninsulated piping requirements.

For insulated piping, consider the effects of external insulationversus internal insulation.

Consider effects of heat tracing piping components.



Ambient Effects (Para 301.4)

CoolingEffects on pressure

Cooling effects of gas or vapor may reduce pressure to cause a vacuum.

Consider external pressure caused by cooling effects

Provide a vacuum break or design piping to withstand external pressure.

Expansion

Fluid expansion effectsMake provisions to withstand or to relieve increased pressure effects due to heating of static

fluid. (Thermal relieving)

Icing

Atmospheric icing effects

Systems operating below 32 of may result in moisture condensation

Make provisions to avoid buildup of iceConsider this condition applying to shut off, control, relief valves.

Low Ambient Temperature

Consider for displacement stress analysis



Dynamic Effects (Para 301.5)

Impact

External - jet impingement

Internal - water hammer (any liquid), liquid or solidslugging, flashing

Wind

Minimum design loads for buildings and structures

Uniform Building Code, ASCE 7 (ANSI 58.1)

Earthquake

ASCE 7

Uniform Building Code

ff 301



Dynamic Effects (Para 301.5)

VibrationDesign to reduce excessive vibration

consider implementing studies to determine if resonance will occur in some part of the system.Consider use of pulsation-reducing devices (accumulators, surge drums etc.)

Supports Adequate foundations, especially at pumps and compressors

strategic location of guides and supports avoidance of small branch connections

Impact, pressure pulsation, resonance wind loads

Discharge Reactions

design, arranged and supported

let down loads

relief valve discharge loads



Weight Effect (Para 301.6)

Live Loads

Medium weight - service or test

Environmental - ice & snow

Dead Loads

Piping component weight

Piping insulation

Other superimposed permanent loads

Thermal Expansion and Contraction Effects



Thermal Expansion and Contraction Effects

(301.7)

Thermal Loads Due to RestraintsThermal expansion thrust and moments

Restraints and anchors

Equipment connections - pump, tank connections

Loads Due to Temperature GradientsUnequal temperature distribution (dead leg)

High heat flux

Two phase flow (condensate line)

Loads Due to Differences in Expansion CharacteristicsBimetallic piping (differences in thermal expansion)

Lined piping

Jacketed

Metallic-non metallic piping

Oth C diti



Other Conditions

EFFECTS OF SUPPORT, ANCHOR AND TERMINAL MOVEMENT (Para. 301.8)Piping flexibility

Settlement

Wind sway

REDUCED DUCTILITY EFFECTS (Para. 301.9)

Welding

Heat treating Forming, bending or low temperature operation

Chilling effect (evaporation of volatile liquid)

CYCLIC EFFECTS (Para. 301.10) (Thermal or Pressure)

Fatigue effects

Cyclic loadings

AIR CONDENSATION EFFECTS (Para. 301.11)

At operating temperature below -3 12° F (-191° C) in ambient air, condensation and oxygenenrichment occur.

Materials selection

Include insulation and adequate shielding and/or disposal

Design Conditions



Design Conditions

Appendix F

Good reference in the form of precautionary considerations relating to particular fluid services and piping applications

The designer is referred to Appendix F of ASME B31.3 for guidance in the form of precautionary considerations relating to particular fluid services and pipingapplications. These are not Code requirements but should be taken into accountas applicable in the engineering design. Appendix F provides further informationand references in the following areas:

Design Conditions

Ambient Effect (fluid entrapment)

Dynamic Effects

Thermal Expansion and Contraction Effects (bowing during cool down)

Pressure DesignPressure Design of other Metallic Components (Expansion Joints)

Valves

extended bonnets are recommended to establish a temperature differencebetween valve packing and fluid.

D ig C diti



Design Conditions

APPENDIX F (Cont’d)

Flanges and Gaskets Specific Flanges (raised face flanges)Gaskets (full face type)

Bolting - use of controlled bolting procedures. The most widelyused bolting materials in process plant design are ASTM A193Grade B7 Stud bolts with ASTM A194 Grade 2H heavy hex nuts.These materials are acceptable from - 50° F to 1O00°F.

Flanged Joints - selection/design, installation

Design Considerations for Specific Systems

Stop Valves in Pressure Relief Piping! Safeguarding

Design Conditions



Design Conditions

APPENDIX F (Cont’d)

Materials

General Considerations - such as

exposure to fire and melting points

susceptibility to brittle fracture

insulation protection of piping material under fire exposure

susceptibility to corrosion

adverse electrolytic effects

compatibility of lubricants or sealants for threads

compatibility of packing seals, O-rings

Specific Material Considerations (Metals)

cast iron/lack of ductility, sensitive to thermal and mechanical shocks . conversion of carbides to graphite during long-term exposure above

800°F for carbon steels

hydrogen exposure

possibility of stress corrosion cracking

susceptibility of high alloy (stainless steels) in inter-granular corrosion comments and considerations in the use of:

Nickel and Nickel Based Alloys

Aluminum and Aluminum Alloys

Copper and Copper Alloys

Titanium and Titanium Alloys

Zirconium Alloys

Tantalum



DESIGN CRITERIA

General Pressure Temperature Design Criteria

Allowable Stresses and Other Stress Limits (Para

302.3)

28

Design Criteria



Design Criteria

General Pressure-Temperature ratings can be used for piping components listed in

Table- 326-1The standards list the dimensional requirements for piping components

Appendix-A of the Code is a requirement also

Allowances for Pressure & Temperature variations

Variations occur on occasionsUse these variations to determine the design conditions

Rating at Junctions of Different Services Separating valve rated at highest service (most severe service condition)Design each side to service condition applicable

Design Criteria



Allowable Stresses and Other Stress LimitsDetermine stresses in accordance with Code Rules unless modified by other

provisions of this Code

Tension - The basic allowable stress S in tension is listed in Table A-I of thiscode.

Table A-I is used to determine the allowable stress in tension for a number of metallic components at various temperatures. When using Table A-I take care to

read any notes which may apply to the specific material.When the term SE appears in an equation, the stress value S is multiplied by a

manufacturing quality factor E. The term E will have a subscript c or j. Subscript cmeans that the component has a casting quality and subscript j relates to weldquality. The values of Ec and Ej are found in Code Tables A1-A and A1-Brespectively.

Shear and Bending - The allowable stress in shear shall be 0.80 of the basic

allowable stress in tension from Table A-l or A-2.Bearing - The allowable stress in bearing shall be 1.6 times the basic allowable

stress in tension

Compression -The allowable stress in compression shall be no greater than thebasic allowable stress in tension. Structural stability shall be considered.

Design Criteria

Design Criteria



Design Criteria

Basic Allowable Stresses used for Internal & External Pressure S =basic allowable stress from Table A-1at minimum metal temperature considered safe when wall

thickness meets the requirement of para. 304 (for internal pressure) and ASME BPV Code, Section VIII,Div. 1 (for external pressure)

Basic Allowable Stresses used for Fatigue or Cyclic Loads

Sc =basic allowable stress at minimum metal temperature expected during the displacement cycle under analysis

Sh = basic allowable stress at maximum metal temperature expected during the displacement cycle under

analysis The above basic stresses are used to calculate the allowable displacement stress range, SA, which is used

for fatigue analysis

Bases for Allowable Stresses(other than Bolting, Cast & Malleable Iron)

Allowable stress for a pipe or component is based on a function of the yield or tensile strength of thematerial, or the creep rate at temperature or stress for rupture at elevated temperature. Reference Para.302.3.2.

Allowable stress for material at ambient or cold condition is given the term Sc.

Allowable stress for material at the design temperature is given the term Sh.

Sc and Sh values are tabulated in Table A-I. The basis of Sc and Sh values at temperatures below thecreep range are the lowest of 1/3 of the specified minimum tensile strength at room temperature.

1/3 tensile strength at temperature.

2/3 minimum yield strength at room temperature.

2/3 yield at temperature.

Design Criteria



Design Criteria

Who Can Establish Allowable Stresses

The user can not establish or calculate the allowable

stresses.

Only the ASME Code Committees can establish

allowable stresses.

For a user to use a new material, he/she needs to

provide to ASME the necessary material data, i.e. tensile

strength and yield strength at various temperatures, creep

data and stress-strain curves. Appendix 3 of Section-IIPart D describes the complete information that ASME

requires.



PRESSURE DESIGN (PARA304)

Straight Pipe (Para 304.1) Branch Connection (Para 304.3) Calculation

Wall Thickness for Internal Pressure



(Para 304.1)

For (t < D/6)

=

2 +

c = Corrosion Allowance

P = Internal design pressure

D = Outside diameter of pipe

S = Stress Value from Table A-1Y = Stress Temp compensation factor from Table 304.1.1

E = quality factor from Table A-1A or A-1B

Mill tolerance 12.5%

T = t + c + mill tolerance

For t ≥ D/6 or for P/SE > 0.385

calculation of pressure design thickness for straight pipe requires special consideration of

factors such as theory of failure,

effects of fatigue, and thermal stress.

Branch Connection (Para 304 3)



Branch Connection (Para 304.3)

Reinforcements to be added based on geometry of area.

Not required when connections are taken using listed/listed unratedcomponents

Conditions

1. Centre line of branch pipe intersects that of run

2. Angle of intersection is between 45 and 90 deg

3. For run pipeℎ

ℎ< 100

4. Branch to run dia ratio

ℎ< = 1

Branch Connection (Para 304 3)



Branch Connection (Para 304.3)

Integrally reinforced branch fittings which abut the run pipe above 4 inch dia

are not permitted if d/D exceeds 0.8 or run pipe is less than sch 40 or run

pipe thickness is less than 0.74 where pipe size exceeds 36 inch

Pad reinforced braches where temp exceeds 800°F are not permitted

Branch connections 1.5 inch or lesser can be made using half coupling or

pipe nipple 160 sch.

Branch Connection Calculations



= = − −

= = −

[ = − + − +

, ]

= = − − −

= = . − . − +

= = − −

= = −

×

= = + +

<

= =

+

= × .

Branch Connection Calculations

37

Sample Problem – Branch Reinforcement



Pipe Material: Seamless, A106 Gr. B for branch andheader

S = 16,500psi

Design Conditions : 550 psig @ 700°F

c = 0.0625inMill Tolerance = 12.5%

NPSHeader : 0.562in

Branch : 0.375inRequired Pipe thicknessesHeader : 0.395in

Branch : 0.263in

Branch Angle = 90°

Sa p e ob e a c e o ce e t

38




p

39

Calculate Required Reinforcement Area

= = − −

= − . × . − .

= .

= = − = . × . − = .




p

40

Calculate Excess Area Available in Header

= = − − − [ = − + − +

, ]

= = . < = = × . − . . × . − . − . = .




p

41

Calculate Excess Area Available in Branch

= = − −

= = . − . − +

= . . × . − . = . =

× . . × . − . − .

= .




p

42

Calculate Other Excess Areas Available

= = −

× ≈

= = + +

= . + . + = .

<




43

Reinforcement pad: A106, Gr. B, 0.562 in. thick

Recalculate Available Reinforcement = . − = . . × . − . = .

= . − + = . . × . − . + . . = .

= .

= × . . × . − . − .

= .

= = + +

= . + . + = .




44

Calculate additional reinforcement required and pad

dimensions: = 6.11 − 0.535 = 5.575

, :

= 0.562 0.875 = 0.492

= =

+

=

5.575

0.492+ 16 = 27.3

2 > ,



FABRICATION, ASSEMBLY &ERECTION

45

Fabrication



Welding/ Requirements

Preheating/ Heat Treatment

Bending and Forming

Assembly & Erection



Alignment

Flanged Joints

Threaded Joints

Tubing Joints

Cleaning of Piping

FABRICATION, ASSEMBLY & ERECTION



WELDING

Welding procedure & Performance qualification as per

Sec. IX with some exceptions as defined in para. 328.2.1

(b) to (f)

Welding Procedure Qualification by others (other thanowner) maybe used provided that the conditions of para

328.2.2 (a) are met.

Performance Qualification by others maybe acceptable

as per para 328.2.3

Welding joints & alignment of joints




WELDING REQUIREMENTWelding shall be made by qualified welders by qualified

procedure

Tack welds at the root shall be made with filler metal

equivalent to that used in the root passPeening is prohibited

Welding shall not be performed if there is impingementon the weld area of rain, snow, sleet or excessive wind or if the weld area is frosted or met.

FILLET WELDS

Branch Connection



PRE-HEATINGPre-heating is used to minimize the detrimental effects of high temperature &

severe thermal gradients inherent in welding

Required & recommended minimum heat temperatures are given in Table 330.1.1

If the ambient is below 0°C, the recommendations become requirements

HEAT TREATMENT

Heat Treatment is used to avert or relieve the detrimental effects of hightemperature & severe gradients inherent in welding & to relieve residual stressescreated by bending & forming

Heat treatment shall be in accordance with the material grouping & thicknessranges as defined in Table 331.1.1

Governing thickness criteria is defined in para. 331.1.3Fillet welds also required heat treatment as per para. 331.1.3 (b). Heat treatmentis required when the thickness through the weld in any plane is more than twicethe min. material thickness requiring heat treatment

Hardness tests of production welds & of hot formed piping are intended to verifysatisfactory heat treatment




BENDING & FORMINGPipe maybe bent & components maybe formed by any

hot or cold method suitable for the service.

The finished surface shall be free of cracks & buckling.

Thickness after bending shall be not less than thatrequired by the design.

Both hot & cold bending is allowed provided that the heat

treatment is carried out as per para. 332.4




ASSEMBLY & ERECTION

Alignment

Piping Distortion - Any distortion of piping to bring it into alignment for joint assembly which introduces adetrimental strain in equipment or piping components is prohibited

Cold Spring - To be discussed during PEP session on Flexibility Analysis

Flanged Joints - Before bolting up, flange faces shall be aligned to the design plane within 1mm in 200mmmeasured across any diameter; flange bolt holes shall be aligned within 3mm maximum offset.

Flanged Joints

Tightening of bolts to a predetermined torque is recommended

Bolts should extend completely through their nuts. Any which fails to do so are considered acceptablyengaged if the lack of complete engagement is not more that one thread

No more that one gasket shall be used between contact faces in assembling a flanged joint

Threaded Joints

Sealing compound used on threads shall be suitable for the service conditions & pipe material

Joints to be seal welded shall be made up without sealing compound

A leaking threaded joint maybe seal welded provided all compound is removed from exposed threads




ASSEMBLY & ERECTION (Cont’d)

Tubing Joints

Both flared & flareless (compression type) tubing joints

are permitted

Cleaning of Piping

Refers appendix-F, para. F335.9 (Appendix-F is for

guidance)



INSPECTION, EXAMINATION &TESTING

55

INSPECTION, EXAMINATION & TESTING



B 31.3 distinguish between Examination & Inspection

Examination

Applies to quality control functions performed by the manufacturer (for components only), fabricator or erector.

Responsibility for Examination Providing materials, components, and workmanship in accordance with this code

Performing all required examinations Preparing suitable records of examinations & tests for the Inspector’s use

Inspection

Applies to functions performed for the owner by the owner’s Inspector or the Inspector’s delegates.

Responsibility for Inspection It is the owner’s responsibility, exercised through the owner’s Inspector

Verify that all required examinations & testing have been completed

Inspect the piping to the extend necessary to be satisfied that it conforms to all applicable examination requirements of theCode and of the engineering design

Qualification of Owner’s Inspectors

Defined in para. 340.4




INSPECTION & EXAMINATION (Cont’d)

Examination Requirements

Prior to initial operation each piping installation, including components & workmanship shall be examined(in accordance with para 341)

Extent of Required Examination

Visual Examinations

Sufficient materials & components, selected at random, to satisfy the examiner that they conform to

specifications and are free from defects At least 5% of fabrication for welds, each welder’s work shall be represented

100% of fabrication for longitudinal welds except those in components made in accordance with a listedspecification

Random examination during erection of piping including checking of alignment,

supports & cold spring

Examination of erected piping for evidence of defects that would require repair or replacement and for other evident deviations from the intent of the design

Other Examinations

Not less than 5% of circumferential butt & miter groove welds shall be examined fully by randomradiography or ultrasound

The welds to be examined shall be selected to ensure that the work product of

each welder doing the production welding is included




INSPECTION & EXAMINATION (Cont’d)

Examination - Severe Cyclic Conditions

More stringent inspection requirement (refer para.

341.4.3)

Acceptance Criteria

For welding, refer Table 341.3.2.

For others, as per engineering design

Testing



Requirements for Leak TestPreparation of Leak Test

Test Fluid

Test Pressure

Hydrostatic Testing of Piping with Vessel as a System

Pneumatic Leak Test




TESTING

Required Leak Test

Prior to initial operation, each piping system shall be tested to ensure tightness. The test shall behydrostatic leak test in accordance with para. 345.4.

Where the owner considers a hydrostatic leak test impracticable, either a pneumatic test or a combinedhydrostatic-pneumatic test maybe substituted.

Where the owner considers both hydrostatic & pneumatic leak testing impracticable, the alternativespecified in para. 345.9 maybe used

Para. 345.9 - Alternate Leak Test

100% Examination of longitudinal, circumferential & spiral groove welds by radiography

100% Examination of structural attachment welds by PT or MP

Carry out formal flexibility analysis

General Requirement for Leak Test

Test pressure should not exceed beyond Yield Strength

Precaution should be taken for over pressurization due to fluid thermal expansion

Test shall be maintained for atleast 10min. for leak detection Piping sub-assemblies may be tested either separately or as assembled piping

A flanged joint at which a blank is inserted to isolate other equipment during a test need not be tested

Piping subject to external pressure shall be tested at an internal gage pressure 1.5 times the externaldifferential pressure, but not not less than 15 psi.




TESTING (Cont’d)

General Requirement for Leak Test (Cont’d)

Jacketed Lines - The internal line shall be leak tested on the basis of the internal or external design pressure, whichever iscritical. The jacket shall be leak tested separately.

If repair or additions are made following the leak test, the affected piping shall be

retested, except that for minor repairs or additions the owner may waive retest requirements when precautionary measures aretaken to assure sound construction

Preparation for Leak Test All joints to be leak tested are to be left un-insulated & exposed for examination during the leak test

Piping designed for vapor or gas shall be provided with additional temporary

supports, if necessary, to support the weight of test liquid

Equipment which is not to be tested shall be either disconnected from the piping or isolated by blinds or other means during thetest. A valve maybe used provided the valve (including its closure mechanism) is suitable for the test pressure

Test Fluid

The fluid shall be water unless there is the possibility of

damage due to freezing or

to adverse effects of water on the piping or

the process (see para. F345.4.1).

In that case another suitable nontoxic liquid may be used. If the liquid is flammable, its flash point shall be at least 49°C(120°F), and consideration shall be given to the test environment.




TESTING (Cont’d)

Test Pressure

Shall not be less than 1.5 times the test pressure at any point in the system

For design temperature above the test temperature, the minimum test pressureshall be calculated by eqn-24, page-83.

Test pressure should not exceed beyond Yield Strength

Hydrostatic Test of Piping with Vessels as a System

Where the test pressure of piping attached to a vessel is the same as or less thanthe test pressure for the vessel, the piping maybe tested with the vessel at thepiping test pressure

Where the test pressure of the piping exceeds the vessel test pressure, and it is not

considered practicable to isolate the piping from the vessel, the piping and thevessel maybe tested together at the vessel test pressure, provided the owner

approves and the vessel test pressure is not less than 77% of the piping test pressurecalculated in by eqn-24, page-83.




TESTING (Cont’d)

Pneumatic Leak Test

Pneumatic testing involves the hazard of released

energy stored in compressed gas.A pressure relief device shall be provided, having a

set pressure not higher than the test pressure plus thelesser of 50psi or 10% of the test pressure

Test Fluid - The gas, if not air, shall be nonflammableand nontoxic

Test Pressure - 110% of the design pressure

QUESTION



Why is “B31.3” called B31.3?

In 1926 the American Standards Association (ASA) initiated theB31 Project at the request of the American Society for Mechanical Engineers (ASME). At that time, there were 31

known formulae for the calculation of pipe thicknesses.

One of the prime task of B31 project team was to analyze/ testthese formulae to establish the most appropriate/ acceptableformula for the pipe thickness calculation

asme b31.3 overview

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